Multiscale indicator



March 12, 1940. Egan/ms MULTISCALE INDICATOR Filed Nov. 50,1936 2 Sheets-Sheet 1 V Enventor March 12, 1940- E, s M ls MULTISCALE INDICATOR 2 Sheets-Sheet 2 Filed Nov. 30, 1936 to Still another object of the invention is to pro- Unless some agency intervenes, light from a 50 Patented Mar. 12, 194.0 9 193 1 7.

UNITED STATES PATE T OFFlCE l 2,193,107 Y p MULTISCALE INDICATOR Elwood S.,Maris, Upper Darby, Pa assignor to Radio Corporationof America, a corporation of Delaware Application November 30, 1936, Serial No. 113,461

2 c aims. (01. 116-4241) This invention relates to multiscale indicators, an opaquesurface having a plurality of transparticularly to tuning indicators for radio appae lucent scales preferably arranged in' equally ratusand has special reference tothe provision spaced parallel relation thereon, a Source of of a translucent multiscale indicator and to means illumination for thescales, which may take the for selectively illuminating the scales. form of an illuminated pointer, and a mask of 5 Modern radio receiving sets areusually capaspecial design mounted for movement intermeble of translating not only frequencies within the diate said source and the scale bearing surface. standard broadcast range but also frequencies The mask hasa plurality of slots therein so within the intermediate, high and low frequency spaced with respect to the translucent scales that 9 ranges. It is' desirable, in order to avoid conupon alignment of is, given slot with a selected 10 fusion, that some positive indication be given of scale the other of said slots will lie adjacent the particular waveband in use. To this end, it opaque porti ns f t Scale bearing surface has previously been proposed to selectively. frame whereby but a single scaleis illuminated at any the several scales as the wave bands are changed given moment. A traveling pointer common to in discrete. steps by means of a multiposition all of the scales is disposed behind the mask; it 15 switch. :I'hus, one known type of tuning indlis preferably illuminated throughout its length cator employs a glass plate upon which the scales but since at any given moment the mask con- ,are marked in spaced parallel array. The scale ceals all but one of the scales the indication probearing surface is illuminated fromthe rear and d d by the pointer is Visible adjacent only t 21) means are provided for lifting the plate to bring one of said scales.

the scales selectively into register with an aper- Certain details of construction, together with V ture in the .front panel of the set. Another other objects and advantages will be apparent known device employs a similar, but rigid, scaleand the invention itself will be best understood bearing glass plate with a'movable mask disposed by ref n to the following specification n t0 .13 between the source of illumination and the plate. H the accomp ny r w w r n: 25 The mask is provided with a slit of a contour Fig. 1 is a front elevation of a five-band tuning similar to that of the scales so that when th scale and shutter or mask therefor, a portion of slit is in register with a given scale, that scale, the fr me s pp the scale-bearing rf c only, is illuminated. being broken away to show a pointer and pointer In; One very real. objection to indicators of the OV ech type described is that they occupy too much space. 2 is sefltional eleVationltaken 0n t e line That this is so will be apparent when it is app're- 2 O and r ciat'ed that the space required to permit of move Figl 3 S fragmentary elevation, of an ment of the scale, or mask through its ntir alternative form of shutter and pointer for a.

range of movement is substantially twice that of fi Scale of 3 type ShOWn in n 35 the actual dimension (in thedirection of move- In Figs. 1 and F designates a -pa e 0 ment) of the plate upon which the scales are frame which carries a plate P formed of glass marked. l or other translucent material; brackets B and Accordingly, an object of the present invention fi respectively to the horizontal and t it is to provide a multiscale indicator wherein the cal edges of the frame Serve Secure e plate 40 cabinet space required to accommodate the de- Pag'ainst movement. Plate P has a plurality of vice is of a substantially constant and minimum scale areas 2, 4, 6, 8 and ill, arranged thereon. area irrespective of any necessary relative move- These areas are translucent and the spaces I, 3, ment between the scale and the scale-framing or 5, i, 9, H, between them have beenrendeied scale masking device. opaque as bya coating or filmC (Fig. 2) of paint,

Another object of the invention is to provide a dark paper or the like. The scale indicia maybe multiscale indicator wherein a desired indication of any suitable type; for instance, as indicated may be achieved by the application of minimum on scale l, they may comprise semi-transparent torque, or other force, to the device. markings m spanning the transparent scale areas.

vide asimple, compact, inexpensive and troublesource 60 (later described), impinging on the free multiscale indicator and one which lends rear of plate P, will illuminate all of the scales itself readily to mass production methods. 2, 4, 6, 8', and i9, simultaneously;

The above and other objects are achieved, in For the purpose of confining illumination to a 65. accordance with the invention, by the provision or" selected single scale, the present invention conbe, a similar number of steps.

templates the use of a mask M of special design, mounted for vertical movement intermediate the light source and the rear surface of the scale bearing plate P.

This mask M contains a plurality of slots therein, so spaced with respect to the translucent scale areas that upon alignment of a given slot with a selected scale, the other of the slots will lie adjacent opaque portions of the scale bearing surface P. This ensures that but a single scalewill be illuminated at any given moment.

The mask M of Figs, 1 and 2 contains four apertures or slots 22, 24, 26, 28, whose dimensions are preferably slightly larger than the dimensions of the translucent scale areas on plate P. The slots are equally spaced one from another and the space between them is greater than the space between adjacent of the scales.-

On a five-band indicator, successfully operated, the scale areas were each and were spaced from each other whereas the four slots in the mask were each es and were spaced }2-" from each other. Thus, as shown in Fig. 1, when the top slot 22 is in register with the top scale 2, slot 24 is behind the opaque portion 5 between scales 4 and 6, slot 26 is behind the opaque portion 9 between scales 8 and I0, and slot 28 is behind the opaque portion II beneath the bottom scale I0.

The mask is adapted to be moved up and down in discrete steps by means of a knob (not shown) fixed on the terminal of a shaft 30 which is connected to a suitable wave-change mechanism 32 (Fig. 2). Lever arms 34 and 36 extend from this shaft 3i] to a slotted cam 38 which is pivoted for rotation about an axis 40. A cam follower 42 fixed to the mask M ridesin the slot 44 in cam 38 so that when the wave-change mechanism is moved in discrete steps,"the follower 42 and hence the mask M is moved up or down, as the case may 7 The mask M moves in brackets 46, 48 fixed to the back of frame F. As shown in Fig. 2, a central guide, in the form of a short rod 50 which travels in a guideway 52 may also be provided if desired.

The source of illumination, pointer, and pointer moving mechanism for use with the scale plate P and shutter M of Figs. 1 and 2, may be of any suitable or convenient type. In the embodiment referred to the only illumination appearing adjacent a selected scale is a line or pointer of light .projected through a slot 62 in a housing or shield 64 which is mounted for movement behind the mask The interior of shield 64 may be painted white, orit may be polished, to project light provided by a lamp 60 upon the unmasked rear surface of a selected scale. Lamp 60 and its shield 64 are fixed to a bracket 66, and the bracket is slidably mounted upon an edge 68 of a rear mounting plate or frame F The pointer assembly is moved transversely of the scale bearing surface P, by means of a taut j is carrying the main tuning element 80 of the set.

Shaft i8 carries a gear 82 which meshes with a driving gear 84 fixed on tuning shaft 86 which extends throughthe front panel of the set.

A desired band having been selected by movement or the wave change shaft 30, and with the mask M moved into position to permit the illuminated pointer to be viewed adjacent the scale individual to the band selected, tuning is accomplished by rotating the tuning shaft 86. This drives the condenser shaft 18 through gears 82 and 84. Since the central pulley 16 about which cord H1 is wrapped, is fixed on shaft 18, it too will rotate, causing the pointer 64 and its bracket 66 to move transversely across the scale in the direction of movement of the tuning shaft 18.

V In the embodiment of the invention shown in Fig. 3, a rod-like unilluminated pointer 96 is disposed between the scale bearing surface P and its mask, here designated M'. This pointer 98 travels in front of a general source of illumination, indicated by lamps 92 and 94, so that the pointer providesan opaque indication upon a single scale which is illuminated throughout its length. The scale bearing surface P, like that of Figs 1 and 2, carries five frequency band scales. The mask M, however, contains but three slots I22, I 24 and I 26 therein. In an actual embodiment of the invention, where the individual scales were and the opaque region between each adjacent pair of scales was the apertures in the mask measured and were spaced ts" from each other.

As shown in the drawings, the central slot I24 is in register with the middle scale area .5, whileslots I22 and E26 lie adjacent opaque sections 3 and 9, respectively, so that only scale 6 receives light from lamps 92 and 94.

The mechanisms for moving the pointer and the mask will be understood to be similar to those shown in Figs. 1 and 2. If the maskM' is moved up one step, slot I22 will register with scale 2. If moved down one step, slot I26 will register with scale I0. In order to illuminate scale 8 the mask must be moved up two steps, in which case slot I26 will be in register with it. To provide illumination for scale 4 the mask is moved down two steps to bring slot I22 in register therewith.

From the foregoing it will be apparent that the cabinet space required to permit of maximum movement of the mask need be substantially no greater than that occupied by the scale bearing surface itself. This permits of the construction of more compact and economical receiver units. Further, the tuning operation is facilitated since the torque required to move the mask is substantially less than that required in apparatus employing scale selecting mechanisms of the prior art.

This invention is not intended to be restricted in scope to the specific embodiments shown, but

contemplate such modifications as are within the spirit of the appended claims.

What is claimed is:

1. An indicator comprising an opaque surface having a plurality of translucent scales arranged thereon, a mask mounted for movement in a plane adjacent and parallel to the plane of said scale bearing surface, a source of light behind said mask, said mask having a plurality of slots therein so spaced with respect to said translucent scales that upon alignment of a given slot with a selected scale the other of said slots will lie adjacent opaque portions of said scale whereby but a single scale is illuminated at a given moment, a pointer mounted for movement behind said scale bearing surface on the side of said mask remote from said scale bearing surface, and means for moving said pointer across said scale bearing surface.

2. An indicator comprising an opaque surface having a plurality of translucent scales arranged thereon, a mask mounted for movement in a plane adjacent and parallel to the plane of said scale bearing surface, said mask having a plurality of slots therein so spaced with respect to said translucent scales that upon alignment of a given slot with a selected scale the other of said slots will lie adjacent opaque portions of said scale, a 

